Isaac May Spur New System in the Northern Gulf

By By Alex Sosnowski, expert senior meteorologist.

September 07, 2012, 3:10:12 AM EDT

A very slow-moving disturbance, associated in part with the remnants of Isaac, will drift over the north-central Gulf of Mexico and could bring more flooding problems to coastal areas.

Very humid air, combined with the disturbance will unleash downpours and the potential for flash flooding from part of the Louisiana coast to the Florida Panhandle.

Since strong wind shear will increase over the Gulf this weekend, the feature is unlikely to have enough time to develop a strong, low-level circulation. However, a weak system, such as a tropical depression or storm could come about.

Alicia formed from a complex of thunderstorms moving southward over the Gulf of Mexico in 1983. If such a system were to develop and be named, it would "not" gather the name Isaac.

Moisture regenerated from new system could then be drawn up along the Atlantic Seaboard or dragged across the Florida Peninsula over the weekend, enhancing downpours once again.

It appears that the remnants Isaac has split into two parts with one feature over the eastern Great Lakes and the other along the central Gulf coast Tuesday evening.

There is a continued risk of flash flooding from the lingering tropical downpours and any extra enhancement this disturbance provides through the weekend.

During the 24-hour period ending at 1:00 p.m. CDT Wednesday, Mobile, Ala. received 3.60 inches of rain. Pascagoula, Miss. picked up 3.05 inches during the same period as the system drifted slowly southward.

Several inches to a half a foot of additional rain could fall from a slow-moving, weak tropical system anywhere along the central and eastern Gulf Coast area through the weekend.

Cooler, less humid air gathering momentum over Canada is forecast to sweep across Texas this weekend. That air could reach the central Gulf Coast area by early next week providing relief for those sweltering in heat and humidity and dodging downpours in the wake of Hurricane Isaac.